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Is electromotive force equal to supply voltage
First of all, the unit of electromotive force and power supply voltage is the same, both are volt. Because the power supply usually has internal resistance, it will also share part of the voltage in the closed circuit, and the voltage at both ends of the power supply is less than that of the whole power supply. Therefore, in order to distinguish the two different concepts of the voltage at both ends of the power supply and the total voltage of the power supply, The total voltage of power supply is named electromotive force, which means the same quantity and the same value
What is the difference between voltage source and power supply
Power supply can be classified as follows: (1) independent power supply means that the output voltage (current) of the power supply is only determined by the nature of the independent power supply itself, and has nothing to do with the voltage (current) of the rest of the circuit
When the internal resistance of the power supply is zero, is the electromotive force equal to the voltage of the power supply/
Right! When the internal resistance of the power supply is 0, the terminal voltage of the user working in the closed circuit is also the power electromotive force. Because the internal resistance of the power supply is 0, when the current passes through the power supply, there is no work and no energy consumption, so the power electromotive force does not change, that is, the output voltage of the power supply is the same! However, this is an ideal state of physics research, which is impossible in reality!
The following statement about electromotive force is correct ()
A. The electromotive force of the power supply is equal to the potential difference between the positive and negative poles of the power supply. B. the voltage value obtained by directly measuring the two poles of the power supply with a voltmeter is actually slightly less than the accurate value of the electromotive force of the power supply. C. The electromotive force of the power supply is always equal to the sum of the voltages on the internal and external circuits, so its value is related to the composition of the external circuit The electromotive force of the power supply is always equal to the work done by the electrostatic force when the positive charge of 1C passes through the circuit
A. According to Ohm's law of closed circuit, e = u + IR, we know that when the external circuit is open circuit, I = 0, u = e, that is, when the power supply is not connected to the external circuit, the voltage between the two poles is equal to the power supply electromotive force. If the current I ≠ 0 in the circuit, the power supply has internal voltage, and the voltage between the two poles is less than the electromotive force, If there is a certain current in the circuit and a voltage in the internal circuit, the voltage measured by the voltmeter connected between the two poles of the power supply is less than the electromotive force of the power supply. Therefore, B is correct. C. The electromotive force of the power supply is always equal to the sum of the voltages on the internal and external circuits. The electromotive force represents the power supply's ability to convert other forms of energy into electric energy. The electromotive force represents the characteristics of the power supply, which is determined by the power supply itself and is different from the external power supply D. according to the definition of electromotive force E = WQ, we know that the electromotive force of the power source is always equal to the work done by the non electrostatic force when the positive charge passes through 1c in the circuit
RELATED INFORMATIONS
- 1. When the power supply is connected to the circuit, the potential difference between the two ends of the power supply is equal to, less than and greater than the electromotive force of the power supply Such as the title
- 2. What is the electromotive force of the power supply equal to the voltage between the two poles of the power supply when the power supply is open Such as the title Why is it not the voltage between the two poles of the power supply when the circuit is connected?
- 3. Why is it that if the voltage indication number is zero, the circuit of the measured part is short circuited
- 4. A physics problem: there are four resistances, R1 = 1, R2 = 2, R3 = 3, R4 = 4, e = 4V, r = 0.2, total current ——R1——R3—— | | | ——R2——R4—— | | ——||————— R1 and R3 are in one branch, R2 and R4 are in one branch, that is to say, they are connected in series and then in parallel, and there is another line between R1 and R3 and between R2 and R4 The general circuit diagram is like this. The lines in the diagram are all connected Is the middle line useless?
- 5. In the circuit shown in the figure, R1 = 30 Ω, R2 = 10 Ω. After the switch S is closed, the indication of ammeter A is 0.4A. Calculate the power supply voltage, the current through R2 and the current in the main circuit
- 6. How big is the resistance of 5 white LEDs in parallel 12V battery? Repair a small lamp. The resistance is burned
- 7. The voltage is 12 V and there is one 3mm diode. How much resistance do you need? How much resistance do you need for three diodes?
- 8. When a bulb works normally, the voltage is 12 V and the resistance is 24 Ω. If the power supply voltage is 36 V, in order to make the bulb work normally, it is necessary to When a bulb works normally, the voltage is 12 V, and the resistance is 24 Ω. If the power supply voltage is 36 V, in order to make the bulb work normally, what is the resistance in series?
- 9. The bulb marked "6V & nbsp; 3W" is connected in series with an 18 ohm resistor and connected to a 9V power supply. What is the actual power of the bulb?
- 10. A 5V 2W bulb L is connected in series with a 10 ohm resistor R1, and then connected to a stable voltage power supply. The lamp l will light normally L and resistor R2 are connected in series and connected to the same power supply. The power of bulb L is 0.5W. Calculate the resistance of R2
- 11. The b value of triode is the parameter reflecting the ability, which is () a voltage control voltage B current control voltage C voltage control current D current control current
- 12. 1. If the external resistance of the ideal current source increases gradually, its terminal voltage () A. Gradually increase B. gradually decrease C. D. constant Better explain why
- 13. What is the difference between voltage source and current source? Voltage source and current source are the same power supply. I don't know the difference between them. Please answer in detail. Thank you!
- 14. How to judge whether the circuit is short circuit or open circuit from the presence of voltmeter and current indication Students said that in the series circuit, the small light bulb is not on. When the ammeter in series with the small light has a number, the small light is not normal. If the ammeter has no number, it means that the small light is OK. Is he right? Explain it. Thank you
- 15. Why is capacitor equivalent to short circuit at the moment of power on?
- 16. Fill in the blank: ideal voltage source and ideal current source are connected in series, and their equivalent circuit is______ The ideal voltage source and resistor are connected in parallel, and its equivalent circuit is_____ .
- 17. Electrotechnics: the difference between power model and ideal voltage source and ideal current source When the three resistors are connected in series, the voltage and current of the resistor are independent of the voltage source and can be removed
- 18. What determines the voltage at both ends of an ideal current source for circuit analysis What determines the voltage at both ends of an ideal current source The voltage at both ends of the ideal voltage source is determined by ()
- 19. When the voltmeter is paralleled in the circuit under test, what are the consequences of open circuit and short circuit of the voltmeter to the circuit? Forget to say, what if the voltmeter is in series? There are two consequences
- 20. If the power supply is short circuited, the voltmeter will be connected in parallel at both ends. Will the voltmeter be burnt out and display the power supply voltage